In storage networks, it is desired to an access to an LU (Logical Unit) to be limited to a particular server. This is because a server may erroneously access an LU (for example, logical volume (logical VOL)) that is not allowed to be accessed (I/O (Input/Output)) and erroneously update data in the LU.
The LU masking function is known as technology for limiting an access to an LU to a particular server. The LU masking function creates, for each port included in a storage device, an access control list for the LU. The access control list includes a WWN (World Wide Name) of a physical port for an FC-HBA (Fibre Channel-Host Bus Adapter) that is allowed to access an LU in the storage device.
The number of I/O ports (referred to as “storage ports”) in the storage device is conventionally as small as one to two ports, and an FC switch is used to enable accesses from a plurality of servers. In recent years, however, 10 or more storage ports are often mounted, and a storage device can now directly couple a plurality of servers without using an expensive FC switch.